Method of flame-retardant treating blend fabric

ABSTRACT

Disclosed is a method of flame-retardant treating a blend fabric including natural fibers and synthetic fibers to impart flame retardancy to the blend fabric, including treating the fabric with a first flame retardant, primarily tentering the fabric, water-rinsing the primarily tentered fabric, washing the water-rinsed fabric, drying the washed fabric, treating the dried fabric with a second flame retardant, and then secondarily tentering the fabric.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a method of flame-retardant treating a blend fabric, and more particularly to a method of flame-retardant treating a blend fabric which prevents the flame-retardant material of the flame-retardant treated fabric from being discharged to the outside when washed.

2. Description of the Related Art

In order to prevent fire, the importance of flame-retardant function of fibers was rather early emphasized in the developed countries, and there are strong legal prescriptions for the use of flame-retardant fibers for fiber products used in public facilities, children's night clothes, airplanes, automobile seat covers, etc. Also in Korea, laws related to flame retardancy are being gradually enhanced, like the use of flame-retardant fibers in public facilities such as hotels. Alongside the increase in the flame-retardant fiber market, the demand of flame-retardant fibers is expected to become much higher compared to that of general fibers.

Recently, the use of fabrics having flame retardancy is not limited only to public facilities but is widely required in the fields including curtains, sofa cloth, carpet, working clothes, and bedclothes. Accordingly, there is a need for methods of flame-retardant treating a fabric, which generate economic benefits and result in superior flame retardancy.

Methods of imparting flame retardancy to polymer fiber materials are to date largely classified into pretreatment methods and post-treatment methods. The pretreatment methods include methods of copolymerizing a flame-retardant monomer with a polymeric fiber material thus obtaining a polymer having flame retardancy which is then spun, and of adding a flame-retardant material upon spinning and then performing blending. The post-treatment methods include methods of performing graft polymerization of yarn or woven/knitted fabric along with a flame-retardant material, and of adding a flame-retardant material to fabric during dyeing or other processing to thus be penetrated and affixed thereto.

The pretreatment methods exhibit good durability in terms of flame retardancy but are used only in synthetic fibers, and the use thereof is limited depending on the type of fiber material. Of the post-treatment methods, the graft polymerization of the flame-retardant material is vinyl monomer graft polymerization for reacting an unsaturated compound of phosphoric acid ester with a carbon group of cellulose, and thus such a chemical radical reaction results in low reactivity with cellulose. Furthermore, UV rays or electrical rays should be inevitably used, undesirably making it difficult to provide necessary equipment and to achieve industrial production, leading to high costs.

Hence, among the post-treatment methods, adding a flame-retardant material to fabric during dyeing or other processing to thus be penetrated and affixed thereto is typical. This method is known to be spray coating of the surface of a textile product with a bromine- or antimony-based flame retardant, including ammonium phosphate dibasic, sodium tartrate, ferric oxide, manganese dioxide, urea phosphate monobasic, calcium carbonate, and aluminum hydroxide, or immersion of a textile product in a solution of flame retardant material. This method may be applied to all textile products made of natural fibers and synthetic fibers.

Meanwhile, in order to impart flame retardancy to two or more kinds of fibers having different properties, in particular, blend fibers of natural fibers and synthetic fibers, the natural fibers and the synthetic fibers are separately flame-retardant treated, after which the flame-retardant treated natural fibers and synthetic fibers are blended and spun, thus manufacturing the blend fabric having flame retardancy.

However, the manufacturing of such blend fabric is problematic because the natural fibers and the synthetic fibers are separately post-treated, undesirably increasing the manufacturing time and cost, and also because chemical smells are not completely removed after flame-retardant treatment, making it difficult to manufacture such fabric into a product. Furthermore, the flame-retardant material may be discharged to the outside when it is washed, etc.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made keeping in mind the problems encountered in the related art and an object of the present invention is to provide a method of flame-retardant treating a blend fabric, which may eliminate the separate post-treatment of natural fibers and synthetic fibers thus reducing the manufacturing time and cost, and also which may have superior washing durability so that flame retardancy is maintained uniform even upon several washings.

An aspect of the present invention provides a method of flame-retardant treating a blend fabric comprising natural fibers and synthetic fibers to impart flame retardancy to the blend fabric, comprising treating the blend fabric with a first flame retardant and then primarily tentering the blend fabric; water-rinsing the primarily tentered blend fabric; washing the water-rinsed blend fabric; drying the washed blend fabric; and treating the dried blend fabric with a second flame retardant and then secondarily tentering the blend fabric.

In this aspect, the method may further comprise treating the primarily tentered blend fabric with ammonia, between the primarily tentering and the water-rinsing.

In this aspect, the method may further comprise oxidizing the primarily tentered blend fabric, between the primarily tentering and the water-rinsing.

In this aspect, the primarily tentering may be performed by passing the blend fabric treated with the first flame retardant through a first tentering bath at 100˜140° C. at a rate of 15˜25 m/min.

In this aspect, the secondarily tentering may be performed by passing the blend fabric treated with the second flame retardant through a second tentering bath at 170˜210° C. at a rate of 10˜30 m/min.

In this aspect, the first flame retardant may be used to flame-retardant treat the natural fibers of the blend fabric, and the second flame retardant may be used to flame-retardant treat the synthetic fibers of the blend fabric.

In this aspect, the water-rinsing may be repeated four or more times.

In this aspect, the water-rinsing may be performed by water-rinsing the primarily tentered blend fabric in a water-rinsing bath containing water at 25˜85° C. and an alkaline chemical for 1 min or more.

In this aspect, the washing may be performed by washing the water-rinsed blend fabric in a washing bath containing water at 65˜85° C. and a neutral detergent, and then rinsing the blend fabric to remove the neutral detergent therefrom.

In this aspect, treating the blend fabric with the first flame retardant to secondarily tentering the blend fabric may be continuously performed.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view showing a process of flame-retardant treating a fabric according to the present invention; and

FIG. 2 is a flowchart showing the process of flame-retardant treating a fabric according to the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Hereinafter, a method of flame-retardant treating a blend fabric according to a preferred embodiment of the present invention will be described in detail while referring to the accompanying drawings.

FIG. 1 is a schematic view showing a process of flame-retardant treating a blend fabric according to the present invention, and FIG. 2 is a flowchart showing the process of flame-retardant treating a blend fabric according to the present invention.

With reference to FIGS. 1 and 2, according to the preferred embodiment of the present invention, the method of flame-retardant treating a blend fabric comprising natural fibers and synthetic fibers to impart flame retardancy to the blend fabric includes flame-retardant treating natural fibers of the blend fabric using a flame retardant for natural fibers, and flame-retardant treating synthetic fibers of the blend fabric using a flame retardant for synthetic fibers. As such, flame-retardant treating of the chemical fibers is performed after the flame retardant for natural fibers and other chemicals remaining on the chemical fibers are completely removed.

More specifically, this method of flame-retardant treating the blend fabric includes treating the blend fabric with a first flame retardant (S10), primarily tentering the blend fabric (S12), treating the primarily tentered blend fabric with ammonia (S14), oxidizing the primarily tentered blend fabric (S20), water-rinsing the oxidized blend fabric (S22), washing the water-rinsed blend fabric (S24), drying the washed blend fabric (S26), treating the dried blend fabric with a second flame retardant (S30), and performing secondary tentering (S32).

At S10, the blend fabric is immersed in a first immersion bath 10 containing the first flame retardant, so that the natural fibers of the blend fabric are subjected to flame-retardant chemical treatment. As such, the first flame retardant includes those typically used in imparting flame retardancy to natural fibers. In the present invention, for example, Pyrobatex available from Ciba is used. The natural fibers of the blend fabric are imparted with flame retardancy at S10.

At S12, the blend fabric treated with the first flame retardant is primarily tentered. Particularly, the blend fabric is adjusted to a predetermined processing width, after which the blend fabric is dried while passing through a first tentering bath 12 at 100˜140° C. at a rate of 15˜25 m/min.

At S14, the primarily tentered blend fabric is treated with ammonia. Particularly, the blend fabric is supplied into a vapor chamber 14 containing a mixture comprising steam at 70° C. and ammonia at a rate of 15˜25 m/min, and preferably 20 m/min. When the blend fabric is treated with ammonia in this way, the first flame retardant may uniformly penetrate into the blend fabric.

Upon S10 which imparts flame retardancy to the natural fibers of the blend fabric, the first flame retardant and other impurities may be unavoidably added even to the synthetic fibers of the blend fabric, in addition to the natural fibers. When the first flame retardant and other impurities are added to the synthetic fibers of the blend fabric in this way at S10, the second flame retardant which is added to the synthetic fibers to impart flame retardancy thereto is neither penetrated nor affixed to the synthetic fibers at S30, which will be described later, undesirably deteriorating flame retardancy of the blend fabric.

In order to solve the above problems in the present invention, S20 to S26 are carried out, whereby the first flame retardant and other impurities are removed from the synthetic fibers of the blend fabric, making it possible to facilitate the penetration and affixing of the second flame retardant to the chemical fibers at S30.

At S20, the blend fabric which was treated with ammonia at S14 is oxidized. Particularly, the blend fabric is immersed in an oxidizing bath 20 containing an oxidant solution so as to be oxidized. As such, while the blend fabric is oxidized with the oxidant solution, the first flame retardant uniformly penetrated into the blend fabric by ammonia treatment is completely affixed to the blend fabric.

At S22, the blend fabric which was oxidized at S20 is water-rinsed. Particularly, the blend fabric is immersed in a water-rinsing bath containing water at 25˜85° C. and an alkaline chemical for 1 min or longer so as to be water-rinsed, whereby impurities remaining on the blend fabric and the strong chemical smell of the first flame retardant are removed. In order to facilitate the removal of such impurities remaining on the blend fabric and the strong chemical smell, S22 is carried out four times or more, and preferably five times.

At S24, the blend fabric which was water-rinsed at S22 is washed. Particularly, the blend fabric is immersed in a washing bath containing warm water at 65˜85° C., and preferably 75° C. and a neutral detergent for 30 min or longer. Subsequently, in order to remove the detergent, rinsing for 30 min (S25) is performed, so that the first flame retardant residue and other impurities are completely removed from the blend fabric.

At S26, the blend fabric which was rinsed at S25 is dried. Preferably the washed blend fabric is naturally dried, but may be dried using hot air to provide rapid drying.

Through S20˜S26, the first flame retardant, other impurities and so on added to the chemical fibers of the blend fabric are removed, and thus the second flame retardant may be easily penetrated and affixed to the chemical fibers at S30 which will be described below.

At S30, the blend fabric is immersed in a second immersion bath 30 containing the second flame retardant, so that the synthetic fibers of the blend fabric are subjected to flame-retardant chemical treatment. The second flame retardant includes those typically used upon imparting flame retardancy to synthetic fibers, for example, AMGARD CU, CT, etc. The synthetic fibers of the blend fabric are imparted with flame retardancy at S30.

At S32, the blend fabric which was treated with the second flame retardant is secondarily tentered. Particularly, the blend fabric is adjusted to a predetermined processing width, after which the blend fabric is dried while passing through a second tentering bath 32 at 170˜210° C., and preferably 190° C. at a rate of 15˜25 m/min, and preferably 20 m/min.

The blend fabric subjected to S10˜S32 has superior washing durability, and its flame retardancy can thus be maintained uniform even upon several washings.

In the method of flame-retardant treating the blend fabric according to the present invention, only any one step is not performed but S10 to S32 are continuously carried out, thereby increasing the working rate.

Below the blend fabric comprising natural fibers and synthetic fibers was flame-retardant treated using the method according to the present invention, and then washed according to the washing standard of Korea Fire Fighting Corporation as described below, after which the flame retardancy thereof was tested.

The washing standard of Korea Fire Fighting Corporation (which is described in “5. Standard and method (Article 9) for measuring washing resistance of flame-retardant products” of “2. Flame Retardancy Performance Test Method” of the current “Regulations for Test of Flame Retardancy Performance”) is as follows.

1) The number of samples which may be simultaneously washed once is 10 or less.

2) A home drum washing machine having a washing bath with a diameter of 50 cm or more and a depth of 27 cm or more is used.

3) The temperature of water is set to 40±3° C. upon washing and rinsing.

4) A detergent is a neutral detergent, which is added in an amount of 1 g per 1 L of water.

5) A washing cycle of washing for 30 min, two rinsings, and one dewatering is continuously performed five times.

6) Drying is performed using a tumble dryer after completion of five washing cycles.

After five washing cycles according to the washing standard of Korea Fire Fighting Corporation as above, flame retardancy was tested according to standards for flame retardancy performance (KOFEIS 1001). The results are shown in Table 1 below.

TABLE 1 Test Results Sample Test Items Standard 1 2 3 Before After Flame less than 0.0 0.0 0.0 Washing Time 5 sec After Glow less than 0.0 0.0 0.0 Time 20 sec Char Area less than 24.7 24.5 23.1 40 cm² Char Length less than 7.0 7.1 6.7 20 cm Flame 3 or more Not Not Not Contacts Applicable Applicable Applicable After After Flame less than 0.0 0.0 0.0 Washing Time 5 sec After Glow less than 0.0 0.0 0.0 Time 20 sec Char Area less than 23.8 21.7 30.6 40 cm² Char Length less than 6.6 6.6 7.8 20 cm Flame 3 or more Not Not Not Contacts Applicable Applicable Applicable

As is apparent from Table 1, in three test results of curtains made of the blend fabric comprising natural fibers and synthetic fibers which had been subjected to flame-retardant treatment using the method according to the present invention, both the after flame time and the after glow time were 0.0 sec before and after washing, and the char area and the char length were much smaller than the standard values. Thus, flame retardancy of the synthetic fibers can be maintained uniform even after washing.

As described hereinbefore, the present invention provides a method of flame-retardant treating a blend fabric. According to the present invention, the separate post-treatment of natural fibers and synthetic fibers can be eliminated, thus reducing the manufacturing time and cost, and also superior washing durability can be obtained, so that flame retardancy can be maintained uniform even upon several washings.

Although the embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that a variety of different modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Accordingly, such modifications, additions and substitutions should also be understood as falling within the scope of the present invention. 

1. A method of flame-retardant treating a blend fabric comprising natural fibers and synthetic fibers to impart flame retardancy to the blend fabric, the method comprising: treating the blend fabric with a first flame retardant and then primarily tentering the blend fabric, thus obtaining a primarily tentered blend fabric; water-rinsing the primarily tentered blend fabric, thus obtaining a water-rinsed blend fabric; washing the water-rinsed blend fabric, thus obtaining a washed blend fabric; drying the washed blend fabric, thus obtaining a dried blend fabric; and treating the dried blend fabric with a second flame retardant and then secondarily tentering the blend fabric.
 2. The method of claim 1, further comprising treating the primarily tentered blend fabric with ammonia, between the primarily tentering and the water-rinsing.
 3. The method of claim 1, further comprising oxidizing the primarily tentered blend fabric, between the primarily tentering and the water-rinsing.
 4. The method of claim 1, wherein the primarily tentering is performed by passing the blend fabric treated with the first flame retardant through a first tentering bath at 100˜140° C. at a rate of 15˜25 m/min.
 5. The method of claim 1, wherein the secondarily tentering is performed by passing the blend fabric treated with the second flame retardant through a second tentering bath at 170˜210° C. at a rate of 10˜30 m/min.
 6. The method of claim 1, wherein the first flame retardant is used to flame-retardant treat the natural fibers of the blend fabric, and the second flame retardant is used to flame-retardant treat the synthetic fibers of the blend fabric.
 7. The method of claim 1, wherein the water-rinsing is repeated four or more times.
 8. The method of claim 7, wherein the water-rinsing is performed by water-rinsing the primarily tentered blend fabric in a water-rinsing bath containing water at 25˜85° C. and an alkaline chemical for 1 min or more.
 9. The method of claim 1, wherein the water-rinsing is performed by water-rinsing the primarily tentered blend fabric in a water-rinsing bath containing water at 25˜85° C. and an alkaline chemical for 1 min or more.
 10. The method of claim 1, wherein the washing is performed by washing the water-rinsed blend fabric in a washing bath containing water at 65˜85° C. and a neutral detergent, and then rinsing the blend fabric to remove the neutral detergent therefrom.
 11. The method of claim 1, wherein the treating the blend fabric with the first flame retardant to the secondarily tentering the blend fabric are continuously performed. 